Are you refering to RadPropertyGrid or RadGridView, as the former control has a SelectedPropertyDefinitions property and the latter one has SelectedItems? However, both of them are not exposed as DependencyProperties, due to a framework limitation with binding to read-only collection dependency properties that we have encountered. They are not private, but they do not have public setters. This is a common good practice for collection properties, as they are not expected to change their value at runtime. Nevertheless, one can interact with them by modifying their items and their items' properties.